Vassilios or Vassileios, also transliterated Vasileios, Vasilios, Vassilis or Vasilis (Greek: Βασίλειος or Βασίλης), is a Greek given name, the origin of Basil. In ancient/medieval/Byzantine context, it is also transliterated as Basileios. It is directly descended from the word "King", Greek: Βασιλιάς. It descends from the Greek language.